Center punch gauge



Feb. 27, 1951 v. w. JENNINGS CENTER PUNCH GAUGE 2 Sheets-Sheet 1 Filed Dec. 19, 1944 INVENTOR.

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Feb. 27, 1951 v. w. JENNINGS CENTER PUNCH GAUGE 2 Sheets-Sheet 2 Filed Dec. 19, 1944 INVENTOR. 7:24 /4 L/f/V/V/A/6S Patented F eb. 27, T1951 UNITED STATES PATENT OFFICE (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 2 Claims.

The invention described herein may be manufactured and used by and for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to gauges and more particularly to gauges for locating punch marks on fiat work with reference to the edges thereof. It is an object of my invention to provide a center punch gauge for locating punch marks on work, comprising pivotally related scaleshaving adjustable stop means adapted to engage the edges of the work and wherein clamping means are provided for relatively securing the scales so that identically located punch marks may be located on a plurality of identical pieces of work. It is a further object of my invention to provide a structure having simplicity and ease of operation and wherein the clamping means for securing the scales in relatively fixed position is not readily subject to misadjustment in the handling of the gauge. In accordance with the above objects, I provide scales pivotally associated with each other and having a punch member reciprocably disposed in axial relationship with the pivot axis of the scales, there being adjustable stop members slidably disposed on the scales, the gauge as thus constructed being usable in conjunction With non-rectangular work as well as rectangular work, as will be understood from the following detailed description with reference to f the appended drawings, in which:

Fig. 1 shows a general exterior view of the device in relation to a piece of work;

Fig. 2 shows a cross section through 2-2 of Fig. 1;

Fig. 3 shows a modification of the device; and

Fig. 4 is a cross section through 4-4 of Fig. 3.

With reference to Figs. 1 and 2, scales I and 2 are shown calibrated in linear units reading outwardly from the axis of a punch member 3, and having slots 4 and 5, respectively, in which are slidably arranged stop members 1 and 8, having edges 9 and I perpendicular to the slots 4 and 5 and adapted to be aligned with indicia of the scales and to be held in adjusted position by tightening securing knobs II and I2 which are threadedly secured to studs Ila and I2a secured to stop members 7 and 8, respectively, and. protruding upwardly through slots 4 and 5, respectively. The scales I and 2 are pivotally secured by a member I5 which terminates in a ring-like collar I5 protruding through suitably provided bores in the scales at their inner extremities, and having an outwardly flanged end I6a for holding the scales together in a manner permitting pivotal freedom thereof. The punch memher 3 is reciprocably disposed. within the support member :5 and is biased to upward position by a spring I 8 retained within the support member I5 and abutting a flange 20 on punch member 3. Scales I and 2 have formed therewith at their outer extremities arcuately spaced extension members 2! and 22, respectively,.which are segments of circles about the axis of punch member 3 and are adapted to rotate insliding contiguity with each other as scales I and 2 have their angular relationship changed by'pivotal motion about the axis of punch member 3. The extension members 21 and 22 are provided with slots 24 and 25, resectively, and a securing means is'provided comprising a block 2'! having an upwardly protruding stud 28 passing through slots 24 and 25 for threadedly engaging a securing knob 29. Thus any angle up to may be obtained hereby between these scales I and 2.

To use the gauge, the securing knobs I I and I2 and 29 are loosened and stop members I and 8 spaced from the axis of punch member 3 any desired distance by alignment of the edges 9 and I0 thereon, respectively, with the indicia provided on scales I and 2, the knobs II and I2 then being tightened to secure blocks 1 and 8 in fixed position. The angular relationship between scales I and 2 may then be set in any suitable manner to conform to the edges of any specific piece of work A and the securing button 29 tightened to hold the scales in fixed angular relation. With the edges 9 and ID in contiguity with the edges of the work, a blow is struck on the top of punch member 3 to obtain a punch mark. Since the scales are angularly secured, the gauge may be removed from the work without misadjustment of the relationship between the punch member 3 and the stop members 1 and 8 and may be used on a plurality of identically shaped pieces of work for reproducing identically located punch marks. The arcuately sliding relationship of the extension members 2I and 22 helps to secure by friction therebetween the angular relationship between the scales, and since there is only one pivotal point provided in the device, namely, through the axis of punch member 3, the possibility of angular misadjustment due to rough handling is minimized.

With reference to Figs. 3 and 4, a modification of the clamping means is shown comprising a wing nut 30 threadedly engaging the exterior of the support member I5 and being thereby adapted to clamp the inner extremities of the scales I and 2 together against the flanged end I6a of support member I5, as will be clearly understood from consideration of Fig. 4. This makes for a simpler and lighter structure than the form of the invention disclosed in Fig. 1, but obviously does not provide the same degree of security as the arcuately spaced extension members 2| and 22 which have the advantage of the leverage provided by the lengths of scales I and 2 to resist any turning moment about the axis of punch member 3 tending toward misadjustment.

It will be appreciated that the general structure of my device is not necessarily limited to use with the center punch 3, but may have a guide bushing substituted therefor, the device then being usable in conjunction with a drill press, the guide bushing serving to center the drill directly on the Work without the intermediary step of obtaining a punch mark.

Having described my invention, I claim:

1. A tool for locating a punch point on a piece of relatively fiat stock having an end and two non-parallel opposite edges adjoining said end, where the distances from said point to said two edges are predetermined, said tool comprising two relatively thin bar-shaped scales having an end of one over-lap an end of the other, cylindrical hinge means having its lower end extending through openings in the over-lapping ends to hinge them together so as to be adjustable in angular relation to each other, a cylindrical portion of said hinge means extending upwardly from the upper scale, said cylindrical portion having a concentric opening adapted to receive therein a center punch for duplicate location of punch points on duplicate pieces of stock, linear graduations on said scales, having their zero points at the axis of the hinge point and extending outwardly lengthwise of the scales, guide blocks lying on the under side of the scales having their guiding edges extending crosswise of the longitudinal axes of the scales when bearing against said edges of the stock, adjusting means on said blocks for selectively adjusting said guide blocks along said scales relative to said graduations and for securing said blocks in adjusted positions on said scales, and means to clamp said scales in a selected angular relation.

2. A tool as defined in claim 1 wherein the last said means comprises two arcuate segments, one segment extending integrally from the outer end of each scale and having the free ends of the segments over-lapping, both segments having their common center in the hinge axis, and clamping means to secure said over-lapping ends of the arcuate segments together in any relative angular position of the scales between 0 and VERL W. JENNINGS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 180,095 House July 25, 1876 704,263 Luck July 8, 1902 2,341,875 Malik Feb. 15, 1944 2,349,567 Townsend, Jr., et a1. May 23, 1944 FOREIGN PATENTS Number Country Date 770,759 France July 9, 1934 

